Effect of dipeptidyl peptidase-4 inhibitors on tumor necrosis factor alpha levels in patients with type 2 diabetes mellitus.

AIMS: Dipeptidyl peptidase-4 inhibitors (DPP-4i) served as oral antidiabetic agents for treatment of type 2 diabetes mellitus (T2DM). Although an action on glucose homeostasis was identified, no well-rounded illustration had been established on the changes of tumor necrosis factor alpha (TNF-alpha) levels during DPP-4i treatment. This study aimed to explore the anti-inflammatory effect of DPP-4i on TNF-alpha in patients with T2DM. METHODS: PubMed, Embase and Cochrane Library were systematically searched from inception to May 31, 2024. Randomized controlled trials exploring the impact of DPP-4i on TNF-alpha levels were identified. Risk of bias was assessed according to the Cochrane criteria. A fixed or random-effects model was selected to pool estimate on whether the heterogeneity was present. Subgroup analysis were performed to explore the potential factors that influenced heterogeneity. Related meta-analysis was conducted with the software of Revman 5.3 and STATA 12.0. RESULTS: Eleven trials involving 884 participants with T2DM were included. Pooled estimates suggested that DPP-4i did not significantly modulate TNF-alpha levels (WMD, - 0.70, 95% CI - 1.94 to 0.53, P = 0.26) in T2DM. DPP-4i produced a significant effect on TNF-alpha (WMD, - 4.50 pg/mL, 95% CI - 4.68 to - 4.32, P < 0.00001) when compared to placebo, and a comparable effect was demonstrated on TNF-alpha (WMD, 0.10 pg/mL, 95% CI - 0.11 to 0.30, P = 0.35) in comparison with active agents. Estimate was stable according to the sensitivity test. Subgroup analysis revealed that heterogeneity might not correlate with baseline glycated hemoglobin (HbA1c), age or treatment duration. CONCLUSIONS: A significant effect of DPP-4i on TNF-alpha levels was present in T2DM when compared to placebo. Administration of DPP-4i produced no significant effect on TNF-alpha in comparison with active comparators. Further studies with large samples should be performed to illustrate the impact of DPP-4i on TNF-alpha levels in T2DM. Trial registration International Prospective Register for Systematic Review (PROSPERO) number: CRD42020185479.

Plasticity in single-crystalline Mg3Bi2 thermoelectric material.

Most of the state-of-the-art thermoelectric materials are inorganic semiconductors. Owing to the directional covalent bonding, they usually show limited plasticity at room temperature1,2, for example, with a tensile strain of less than five per cent. Here we discover that single-crystalline Mg3Bi2 shows a room-temperature tensile strain of up to 100 per cent when the tension is applied along the (0001) plane (that is, the ab plane). Such a value is at least one order of magnitude higher than that of traditional thermoelectric materials and outperforms many metals that crystallize in a similar structure. Experimentally, slip bands and dislocations are identified in the deformed Mg3Bi2, indicating the gliding of dislocations as the microscopic mechanism of plastic deformation. Analysis of chemical bonding reveals multiple planes with low slipping barrier energy, suggesting the existence of several slip systems in Mg3Bi2. In addition, continuous dynamic bonding during the slipping process prevents the cleavage of the atomic plane, thus sustaining a large plastic deformation. Importantly, the tellurium-doped single-crystalline Mg3Bi2 shows a power factor of about 55 microwatts per centimetre per kelvin squared and a figure of merit of about 0.65 at room temperature along the ab plane, which outperforms the existing ductile thermoelectric materials3,4.

Photo- and Thermal-Induced Ion Migration and Phase Separation in Mn-Doped Two-Dimensional PEA2PbX4 Perovskite.

Ion migration and phase separation in perovskite materials have negatively affected the solid-state lighting and display. Studying photo- and thermal-induced degradation is considered as a promising approach to understanding the luminescence mechanism and promoting practical applications. Herein, the Mn-doped two-dimensional PEA2PbX4 (X = Cl, Br, I) microcrystals with changing halogen composition were synthesized by an acid-assisted post-processing strategy. Then, photo- and thermal-induced degradation was studied by using steady-state and time-resolved photoluminescence (PL) spectroscopy. The band edge exciton PL peak of Mn-doped 2D PEA2PbX4 microcrystals was adjusted from 397 to 500 nm. The reduced Mn PL lifetime (1.37 to 0.21 ms) was monitored under ion exchange from Cl to Br to I. The degradation mechanism could be divided into two cases: (i) The halide ion migration in Mn-doped 2D perovskite under continuous illumination was revealed, suggesting that the migration of Cl ions was more accessible than that of Br and I. (ii) The PL redshift and lifetime reduction were observed after annealing at 420 K, which means that thermally induced aggregation of Mn ions resulted in the formation of Mn2+-Mn2+ dimers. In addition, the experimental results indicated that the induced B-site phase separation at high temperature annealing made the mixed perovskite phase of Pb and Mn ultimately transform into pure PEA2PbBr4 and PEA2MnBr4.

Scale Effect of Surface Asperities on Stick-Slip Behavior of Zinc-Coated Steel.

Stick-slip behavior between friction pairs causes severe vibration problems such as abrasion and noise pollution, leading to material loss and deterioration in human health. This phenomenon is extremely complex because the surfaces of friction pairs have various asperities with different sizes. Therefore, it is of importance to understand the scale effect of asperities on the stick-slip behavior. Here, we selected four kinds of zinc-coated steels with multiscale surface asperities as a presentative example to reveal what types of asperities play the key role in affecting the stick-slip behavior. It is discovered that the stick-slip behavior is dominated by the density of small-scale asperities rather than large-scale asperities. High-density small-scale asperity increases the potential energy between asperities of the friction pairs, which leads to stick-slip behavior. It is suggested that decreasing the density of small-scale asperity on the surface significantly suppresses the stick-slip behavior. The present study reveals the scale effect of surface asperities on the stick-slip behavior and thus could offer a pathway to tailoring the surface topography of a wide range of materials for suppressing the stick-slip behavior.

Autophagy activation attenuates the circadian clock oscillators in U2OS cells via the ATG5 pathway.

The circadian clock and autophagy are essential biological mechanisms involved in regulating many physiological processes. Accumulating evidence has revealed that autophagic activity is regulated by the circadian clock system. However, whether autophagy regulates the circadian clock system remains unclear. In this study, rapamycin and AICAR, two classical activators of autophagy, were used to create autophagy activation models in BMAL1-dLuc U2OS cell line. The results showed that the mRNA expression of MAP1LC3B and ATG5 were significantly upregulated after autophagy activation, whereas the mRNA expression of circadian clock genes (BMAL1, PER2, REV-ERBα, and DBP) were significantly decreased. Consistent with these data, the relative ratio of LC3-II/LC3-I and the protein level of ATG5 were increased after rapamycin or AICAR treatment. In contrast, BMAL1 and REV-ERBα levels were decreased. Notably, the mRNA expression of circadian clock genes (BMAL1, PER2, REV-ERBα, and DBP) and autophagy-related genes (MAP1LC3B and ATG5) showed rhythmic expression patterns in both untreated and rapamycin/AICAR-treated U2OS cells. Moreover, the autophagy inhibitor 3-methyladenine partially reversed the inhibitory effects of autophagy on circadian clock genes expression and BMAL1-Luc oscillations. Another critical finding was that ATG5 knockout alleviates the inhibitory effect of rapamycin-mediated autophagy activation on the circadian clock oscillators in U2OS cells. Collectively, our data indicate that autophagy activation attenuates the circadian clock oscillators in U2OS cells via the ATG5 pathway.

Two Novel Three-Dimensional Tetraphenylethylene-Based Rare Earth MOFs with Ultra-High Proton Conductivity and Performance Stability.

Invited for the cover of this issue are the groups of Lin Du and Qi-Hua Zhao at Yunnan University. The image depicts astronauts as protons moving along the hydrogen-bond network in the channel of Eu-ETTB/Gd-ETTB. Read the full text of the article at 10.1002/chem.202202154.

Anion-Controlled Assembly of a Silver-Responsive Bifunctional Coordination Polymer with Detection and Large Adsorption Capacity.

The recognition and adsorption of silver ions (Ag+) from industrial wastewater are necessary but still challenging. Herein, we constructed four Zn(II)-based coordination polymers (CPs), namely, [Zn(btap)2(NO3)2]n (1), [Zn(btap)(SO4)(H2O)3]n (2), {[Zn(btap)2(H2O)2]·(ClO4)2}n (3), and [Zn(btap)Cl2]n (4), by using 3,5-bis(triazol-1-yl)pyridine (btap) with different anionic Zn(II) salts. The crystal structures of 1-4, varying from one-dimensional beaded (1) and zigzag chain (2) to two-dimensional sql (3) and bex (4) typologies, were regulated by the coordination modes of btap and the counter-anions. The water stability, pH stability, thermostability, and luminescent properties of the CPs were investigated. The luminescence performances in a series of cations and anions were also explored. Considering the high density of chloride groups in the structure, 4 showed luminescence sensing for Ag+ [KSV = 9188.45 M-1 and a limit of detection (LOD) of 4.9 µM], as well as an excellent ability for Ag+ adsorption in aqueous solution (maximum adsorption capacity, 653.3 mg/g). Additionally, anti-interference experiments revealed that 4 had excellent recognition and adsorption capacities for Ag+ even when multiple ions coexisted. Moreover, XRD, EDS, and XPS analyses confirmed that the coordination of Ag+ with chloride groups in 4 resulted in excellent adsorption capacity and prevented ligand-to-ligand electron transfer, showing excellent detection ability. Suitable coordination sites were introduced to interact strongly with Ag+, along with detection and large adsorption capacity. Our strategy can effectively design and develop multifunctional CP-based materials, which are applicable in removal processes and environmental protection, by regulating anions in the self-assembly and introducing CP functional groups.

Two Novel Three-Dimensional Tetraphenylethylene-Based Rare Earth MOFs with Ultra-High Proton Conductivity and Performance Stability.

In this work, the two example rare earth-based metal-organic frameworks (LaIII -based MOFs), Eu-ETTB and Gd-ETTB, were obtained by self-assembly. Both materials showed extremely high proton conductivity, with the proton conductivity of Eu-ETTB being 1.53×10-2  S cm-1 at 98 % relative humidity (RH) and 85 °C and that of Gd-ETTB being 2.63×10-2  S cm-1 at 98 % RH and 75 °C. This was almost the best performance observed for three-dimensional porous MOFs without post-synthetic modification and was based on milder conditions than for most materials. Furthermore, cycle test experiments and continuous work tests showed that both materials had excellent performance both in terms of stability and durability. Water vapor adsorption experiments showed that a large number of water molecules are adsorbed the hydrogen-bond network's being rebuilt by the adsorbed water molecules in the pore channel and thus optimizing the channels for proton transfer explained the MOF's high performance.

Effect of Wear-Induced Surface Deformation on Stick-Slip Friction of Galvanized Automotive Steels.

This study examined the influence of worn surfaces on the stick-slip friction of galvanized automotive steel and revealed the intrinsic role of surface topography parameters in the stick-slip friction with wear. The results show that the surface deformation induced by wear significantly affects the stick-slip friction. The stick-slip friction can be suppressed by increasing the vertical area of the surface deformation because of reductions in the difference between the static and kinetic friction coefficients. The friction behavior changes from stick-slip friction to smooth sliding when the skewness exceeds a critical value, thus suggesting that this parameter can be used as an effective surface topography parameter to describe the stick-slip friction of galvanized automotive steel with worn surfaces. The findings can help improve the understanding of the mechanism of the stick-slip friction of materials with worn surfaces and provide an approach to suppress the noise and vibration caused by the stick-slip friction of galvanized automotive steel.

NR1D1 targeting CYP19A1 inhibits estrogen synthesis in ovarian granulosa cells.

The circadian system performs an important role in mammalian reproduction with significant effects on hormone secretion. Nuclear receptor subfamily 1 group D member 1 (NR1D1) functions as a transcriptional repressor in the circadian system and affects granulosa cells (GCs), but how it regulates estrogen synthesis has not been clarified. We investigated the effect of NR1D1 on estrogen synthesis and found that NR1D1 was highly expressed in GCs, mainly in cell nuclei. Additionally, the expression of NR1D1 and estrogen synthesis key genes CYP19A1, CYP11A1 and StAR showed rhythmic changes in porcine ovarian GCs. Activation of NR1D1 enhances its ability to inhibit the transcriptional activity of CYP19A1 by binding to the RORE on the CYP19A1 promoter, resulting in a decrease in estradiol content. Interference with NR1D1 can eliminate the transcriptional inhibition of CYP19A1 and promote the synthesis of estradiol. The results suggest that the hormone secretion of the ovary itself is also regulated by the biological clock, and any factors that affect the circadian rhythm can affect the endocrine and reproductive performance of sows, so the natural rhythm of sows should be maintained in production.

Circadian clock regulates granulosa cell autophagy through NR1D1-mediated inhibition of ATG5.

Autophagy of granulosa cells (GCs) is involved in follicular atresia, which occurs repeatedly during the ovarian development cycle. Several circadian clock genes are rhythmically expressed in both rodent ovarian tissues and GCs. Nuclear receptor subfamily 1 group D member 1 (NR1D1), an important component of the circadian clock system, is involved in the autophagy process through the regulation of autophagy-related genes. However, there are no reports illustrating the role of the circadian clock system in mouse GC autophagy. In the present study, we found that core circadian clock genes (Bmal1, Per2, Nr1d1, and Dbp) and an autophagy-related gene (Atg5) exhibited rhythmic expression patterns across 24 h in mouse ovaries and primary GCs. Treatment with SR9009, an agonist of NR1D1, significantly reduced the expression of Bmal1, Per2, and Dbp in mouse GCs. ATG5 expression was significantly attenuated by SR9009 treatment in mouse GCs. Conversely, Nr1d1 knockdown increased ATG5 expression in mouse GCs. Decreased NR1D1 expression at both the mRNA and protein levels was detected in the ovaries of Bmal1-/- mice, along with elevated expression of ATG5. Dual-luciferase reporter assay and electrophoretic mobility shift assay showed that NR1D1 inhibited Atg5 transcription by binding to two putative retinoic acid-related orphan receptor response elements within the promoter. In addition, rapamycin-induced autophagy and ATG5 expression were partially reversed by SR9009 treatment in mouse GCs. Taken together, our current data demonstrated that the circadian clock regulates GC autophagy through NR1D1-mediated inhibition of ATG5 expression, and thus, plays a role in maintaining autophagy homeostasis in GCs.

Multiple Strategies to Fabricate a Highly Stable 2D CuIICuI-Organic Framework with High Proton Conductivity.

Using multifunctional organic ligands with multiple acidic groups (carboxylate and sulfonate groups) to synthesize metal-organic frameworks (MOFs) bearing effective H-bond networks is a promising strategy to obtain highly proton conductive materials. In this work, a highly stable two-dimensional MOF, [CuII5CuI2(µ3-OH)4(H2O)6(L)2(H2L)2]·3H2O (denoted as YCu161; H3L = 6-sulfonaphthalene-1,4-dicarboxylic acid) containing mixed-valence [CuII5CuI2(µ3-OH)4]8+ subunits, was successfully prepared. It exhibited excellent stability and temperature- and humidity-dependent proton conduction properties. Its optimal proton conductivity reached 1.84 × 10-3 S cm-1 at 90 °C and 98% relative humidity. On the basis of a crystal structure analysis, water vapor adsorption test results, and activation energy calculations, we deduced the proton conduction pathway and mechanism. Apparently, uncoordinated sulfonic and carboxyl groups and a network of abundant H-bonds inside the framework were responsible for the efficient proton transfer. Therefore, the strategy of selecting suitable bifunctional ligands to construct two-dimensional Cu-cluster-based MOFs with excellent proton conductivity is feasible.

Circadian regulation of apolipoprotein gene expression affects testosterone production in mouse testis.

The circadian clock system plays an important role in regulating testosterone synthesis in mammals. Male Bmal1-/- mice are infertile with low serum testosterone levels and decreased expression of testicular steroidogenic genes, suggesting that circadian clock genes regulate testosterone biosynthesis by activating steroidogenic gene transcription. However, whether the circadian clock regulates testosterone production via other genes remains unknown. Using Bmal1-/- mice and their wild-type (WT) siblings, we aimed to identify additional genes by which the circadian clock regulates testosterone synthesis. WT and Bmal1-/- mouse testes sections had similar normal morphologies, although there was a decrease in testicular spermatozoa in the Bmal1-/- mice. Low serum testosterone levels were detected in the Bmal1-/- mice. RNA sequencing identified 37 and 48 genes that were differentially expressed between WT and Bmal1-/- mouse testes at circadian time (CT2 and CT14), respectively. The cholesterol metabolism pathway was significantly enriched in the KEGG pathway analysis, and there was lower expression of three apolipoprotein genes (Apoa1, Apoa2, and Apoc3) at CT2 in the testes of Bmal1-/- mice than in those of WT mice. These decreases in Apoa1, Apoa2, and Apoc3 expression were verified by quantitative polymerase chain reaction analysis, which also revealed downregulation of the expression of the circadian clock (Per2, Dbp, and Nr1d1) and steroidogenic (StAR, Cyp11a1, and Hsd17b3) genes. The expression of circadian clock genes was relatively stable in WT mice over a 20-h period, whereas there was clear circadian rhythmic expression of Apoa1, Apoa2, Apoc3, StAR, Cyp11a1, Hsd3b2, and Hsd17b3. Bmal1-/- mice showed severely reduced expression of testicular circadian clock genes at three time points (CT4, CT12, and CT20), and a reduction in mRNA expression levels of Apo (Apoa1, Apoa2, and Apoc3) and steroidogenic (StAR, Cyp11a1, Hsd3b2, and Hsd17b3) genes. Oil Red O staining showed decreased lipid aggregation in the Leydig cells of Bmal1-/- mouse testes. Considering the vital role of Apo genes in high-density lipoprotein formation and cholesterol transport, the present data suggest that the circadian clock system regulates testosterone production by orchestrating the rhythmic expression of Apo genes. These data extend our understanding of the role of the circadian clock in regulating testosterone production in mammals.

Glyphosate exposure attenuates testosterone synthesis via NR1D1 inhibition of StAR expression in mouse Leydig cells.

Glyphosate is a broad-spectrum herbicide that impairs testosterone synthesis in mammals. Leydig cells (LCs), the primary producers of testosterone, demonstrate rhythmic expression of circadian clock genes both in vivo and in vitro. The nuclear receptor NR1D1 is an important clock component that constitutes the subsidiary transcriptional/translational loop in the circadian clock system. Nr1d1 deficiency resulted in diminished fertility in both male and female mice. However, whether NR1D1 is involved in the glyphosate-mediated inhibition of testosterone synthesis in LCs remains unclear. Here, the involvement of NR1D1 in glyphosate-mediated inhibition of testosterone synthesis was investigated both in vitro and in vivo. Glyphosate exposure of TM3 cells significantly increased Nr1d1 mRNA levels, but decreased Bmal1, Per2, StAR, Cyp11a1, and Cyp17a1 mRNA levels. Western blotting confirmed elevated NR1D1 and reduced StAR protein levels following glyphosate exposure. Glyphosate exposure also reduced testosterone production in TM3 cells. In primary LCs, glyphosate exposure also upregulated Nr1d1 mRNA levels and downregulated the mRNA levels of other clock genes (Bmal1 and Per2) and steroidogenic genes (StAR, Cyp17a1, Cyp11a1, and Hsd3b2), and inhibited testosterone synthesis. Moreover, glyphosate exposure significantly reduced the amplitude and shortened the period of PER2::LUCIFERASE oscillations in primary LCs isolated from mPer2Luciferase knock-in mice. Four weeks of oral glyphosate upregulated NR1D1 at both the mRNA and protein levels in mouse testes, and this was accompanied by a reduction in StAR expression. Notably, serum testosterone levels were also drastically reduced in mice treated with glyphosate. Moreover, dual-luciferase reporter and EMSA assays revealed that in TM3 cells NR1D1 inhibits the expression of StAR by binding to a canonical RORE element present within its promoter. Together, these data demonstrate that glyphosate perturbs testosterone synthesis via NR1D1 mediated inhibition of StAR expression in mouse LCs. These findings extend our understanding of how glyphosate impairs male fertility.

Different Phenomena in Magnetic/Electrical Properties of Co(II) and Ni(II) Isomorphous MOFs.

Two unprecedented and stable metal-organic frameworks, {[Co2(H2O)2(L)(OH)]·2.5H2O·0.5DMF} n (1) and {[Ni2(H2O)2(L)(OH)]·1.75H2O} n (2), have been synthesized (H3L = 5-(5-carboxy-pyridin-3-yloxy)-isophthalic acid, DMF = N,N-dimethylformamide). Structural analysis shows that 1 and 2 are heteronuclear isomorphous, possessing a three-dimensional (3D) (4,8)-connected flu/fluorite topological framework formed through the interconnection of tetranuclear butterfly {M4(COO)6(OH)2} clusters and the ligands. Although the frameworks of these two compounds are similar, their magnetic properties are different. Compound 1 exhibits an antiferromagnetic interaction in the high-temperature region, while 2 shows a weak ferromagnetic interaction in the whole-temperature region. Furthermore, considering the presence of hydroxyl groups and water molecules in the frameworks, we tested their proton conductivity. The efficient proton transfer pathway in the framework endowed 1 and 2 with excellent proton conductivities of 9.07 × 10-5 and 1.29 × 10-4 S·cm-1 at 363 K and 98% relative humidity (RH), respectively.

Circadian clock gene BMAL1 controls testosterone production by regulating steroidogenesis-related gene transcription in goat Leydig cells.

Testosterone is produced by Leydig cells (LCs) and undergoes diurnal changes in serum levels in rats, mice, and humans, but little is known in goats. The present study revealed that goat serum testosterone levels displayed diurnal rhythmic changes (peak time at ZT11.2). Immunohistochemical staining showed that BMAL1, a circadian clock protein, is highly expressed in goat LCs. ELISA revealed that both hCG (0-5 IU/ml) and 22R-OH-cholesterol (0-30 µM) addition stimulated testosterone synthesis in primary goat LCs in a dose-dependent manner. Treating goat LCs with hCG (5 IU/ml) significantly increased intracellular cAMP levels. Additionally, real-time quantitative polymerase chain reaction (PCR) analysis revealed that the circadian clock (BMAL1, PER1, PER2, DBP, and NR1D1) and steroidogenesis-related genes (SF1, NUR77, StAR, HSD3B2, CYP17A1, CYP11A1, and HSD17B3) showed rhythmic expression patterns in goat LCs following dexamethasone synchronization. Several Bmal1-Luc circadian oscillations were clearly observed in dexamethasone-treated goat LCs transfected with the pLV6-Bmal1-Luc plasmid. BMAL1 knockdown significantly downregulated mRNA levels of PER2, NR1D1, DBP, StAR, HSD3B2, SF1, NUR77, and GATA4, and dramatically decreased StAR and HSD3B2 protein levels and testosterone production. In contrast, BMAL1 overexpression significantly increased the mRNA and protein expression levels of StAR and HSD17B3 and enhanced testosterone production. Reporter assays revealed that goat BMAL1, or in combination with mouse CLOCK, activated goat HSD17B3 transcription in vitro. These data indicate that BMAL1 contributes to testosterone production by regulating transcription of steroidogenesis-related genes in goat LCs, providing a basis for further exploring the underlying mechanism by which the circadian clock regulates ruminant reproductive capability.

Bmal1 promotes prostaglandin E2 synthesis by upregulating Ptgs2 transcription in response to increasing estradiol levels in day 4 pregnant mice.

Prostaglandin G/H synthase 2 (PTGS2) is a rate-limiting enzyme in prostaglandin synthesis. The present study assessed the role of the uterine circadian clock on Ptgs2 transcription in response to steroid hormones during early pregnancy. We demonstrated that the core clock genes (Bmal1, Per2, Nr1d1, and Dbp), Vegf, and Ptgs2, and their encoded proteins, have rhythmic expression in the mouse uterus from days 3.5 to 4.5 (D3.5-4.5) of pregnancy. Progesterone (P4) treatment of cultured uterus endometrial stromal cells (UESCs) isolated from mPer2Luciferase reporter gene knock-in mice on D4 induced a phase shift in PER2::LUCIFERASE oscillations. This P4-induced phase shift of PER2::LUCIFERASE oscillations was significantly attenuated by the P4 antagonist RU486. Additionally, the amplitude of PER2::LUCIFERASE oscillations was increased by estradiol (E2) treatment in the presence of P4. Consistently, the mRNA levels of clock genes (Bmal1 and Per2), Vegf, and Ptgs2 were markedly increased by E2 treatment of UESCs in the presence of P4. Treatment with E2 also promoted prostaglandin E2 (PGE2) synthesis by UESCs. Depletion of Bmal1 in UESCs by small-interfering RNA (siRNA) decreased the transcript levels of clock genes (Nr1d1 and Dbp), Vegf, and Ptgs2 compared with nonsilencing siRNA treatment. Bmal1 knockdown also inhibited PGE2 synthesis. Moreover, the mRNA expression levels of clock genes (Nr1d1 and Dbp), Vegf, and Ptgs2, and their respective proteins were significantly decreased in the uterus of Bmal1-/- mice. Thus, these data suggest that Bmal1 in mice promotes PGE2 synthesis by upregulating Ptgs2 in response to increases in E2 on D4 of pregnancy.NEW & NOTEWORTHY Rhythmic expression of Bmal1 and Ptgs2 was observed in the uterus isolated from D3.5-4.5 of pregnant mice. E2 increased the expression of Bmal1 and Ptg2 in UESCs isolated from mice on D4. The expression of Ptgs2 was significantly decreased in Bmal1-siRNA treated UESCs. Bmal1 knockdown also inhibited PGE2 synthesis. Thus, these data suggest that Bmal1 in mice promotes PGE2 synthesis by upregulating Ptgs2 in response to increases in E2 on D4 of pregnancy.

Zearalenone perturbs the circadian clock and inhibits testosterone synthesis in mouse Leydig cells.

Zearalenone (ZEA), a mycotoxin, is known to impair reproductive capability by disrupting the synthesis and secretion of testosterone by Leydig cells (LCs), although the mechanism is unknown. Robust rhythmicity of circadian clock and steroidogenic genes were identified in LCs. The aim of this study was to examine whether ZEA significantly attenuated the transcription of core clock genes (Bmal1, Dbp, Per2, and Nr1d1) as well as steroidogenic genes (StAR, Hsd3b2, and Cyp11a1) in mouse testis Leydig cell line (TM3). Western blotting confirmed declines in BMAL1, NR1D1, and StAR protein levels. ZEA also suppressed secreted testosterone levels. In primary LCs, isolated from PER2::LUCIFERASE reporter gene knock in mice, ZEA diminished the amplitude of PER2::LUC expression, and induced a phase shift and period extension. In primary LCs, ZEA also suppressed the expression levels of core clock and steroidogenic genes, reduced protein levels of BMAL1, and decreased testosterone secretion. In vivo expression of core clock and steroidogenic genes were reduced in testes of mice exposed to ZEA for 1 week leading to decreased serum testosterone levels. In summary, data suggest that ZEA may impair testosterone synthesis through attenuation of the circadian clock in LCs culminating in reproductive dysfunction in male mammals .

Bisphenol A attenuates testosterone production in Leydig cells via the inhibition of NR1D1 signaling.

Bisphenol A (BPA) is an endocrine-disrupting compound that impairs testosterone synthesis in male mammals. A circadian clock gene deficiency leads to diminished fertility and even infertility in male mice. However, whether circadian clock signaling pathways mediate the suppressive effect of BPA on testosterone synthesis in Leydig cells (LCs) remains unknown. The present study aims to detect the effect of BPA on cellular circadian clock and testosterone synthesis in mouse LCs, and examine the mechanisms underlying NR1D1 signaling. BPA treatment significantly attenuated the transcription levels of Nr1d1 and steroidogenic genes (Hsd3b2 and Hsd17b3) in TM3 cells, but increased other circadian clock gene levels (Per2 and Dbp). BPA treatment also significantly downregulated NR1D1 and StAR protein expression, but upregulated BMAL1 protein expression in TM3 cells. Furthermore, there was a marked decline in testosterone production in BPA-treated TM3 cells. Intraperitoneal injection of BPA profoundly reduced NR1D1 and StAR protein levels and steroidogenic gene transcription levels (Cyp11a1, Hsd3b2, and Hsd17b3), while enhancing BMAL1 protein and other circadian clock gene (Per2 and Dbp) levels in mouse testes. Notably, serum testosterone levels were also drastically reduced in BPA-treated mice. Moreover, SR9009, an NR1D1 agonist, augmented testosterone production in TM3 cells via elevated expression of steroidogenic genes (StAR, Cyp11a1 and Hsd17b3). Conversely, Nr1d1 knockdown inhibited testosterone accumulation and attenuated steroidogenic gene expression. Moreover, treatment with SR9009 partially reversed the BPA effect on the circadian clock and testosterone production. Taken together, our study demonstrates that BPA perturbs testosterone production, at least partially, via inhibiting NR1D1 signaling in LCs.

Focused Ion Beam-Induced Displacive Phase Transformation From Austenite to Martensite during Fabrication of Quenched and Partitioned Steel Micro-Pillar.

We report evidence of a displacive phase transformation from retained austenite to martensite during preparation of quenched and partitioned steel micro-pillars by using a focused ion beam (FIB) technique. The BCC phase produced by the FIB damage was identified as martensite. The invariant-plane strain surface relief associated with the martensitic transformation was observed in the retained austenite phase immediately after a FIB scan of the surface with the Ga+ ion beam. Use of a low acceleration voltage appears to lower the probability of the phase transformation, while a decrease of the acceleration voltage will result in an increase of the total milling time required to prepare a micro-pillar. This report addresses challenges related to the preparation of austenite micro-pillars by a conventional FIB technique.